Treasure Bags are consumable items obtained in Expert Mode as a reward for defeating bosses. Its contents depend on the boss it comes from. It is opened by either right-clicking it inside the inventory or using it while it is in your hand. In multiplayer, each player that participates in the battle receives one Treasure Bag each. Players can only see and pick up their own Treasure Bag.
Each Treasure Bag contains the boss's usual drops from normal mode, along with one Expert Mode-exclusive item(pink-highlighted items below)— with the exception of the Lunatic Cultist, who currently does not provide an Expert Mode-exclusive item. Hardmode bosses' Bags additionally have a 5% chance to contain one random set of developer items.
A light pet that senses nearby enemies, treasure, and ores
Notes
In Multiplayer, participation is based on damage dealt to the enemy. It is possible for a player to not receive a bag if they did not contribute enough damage to the battle.
Treasure yields are considerably higher in multiplayer- multiple bags are handed out, with each containing the entire reward of a kill, and drop rates on the boss's unique items are often doubled.
History
1.3.0.4: Fixed Treasure Bags disappearing after death.